1 # SPDX-License-Identifier: GPL-2.0
2 #
3 # gdb helper commands and functions for Linux kernel debugging
4 #
5 # Kernel proc information reader
6 #
7 # Copyright (c) 2016 Linaro Ltd
8 #
9 # Authors:
10 # Kieran Bingham <kieran.bingham@linaro.org>
11 #
12 # This work is licensed under the terms of the GNU GPL version 2.
13 #
14
15 import gdb
16 from linux import constants
17 from linux import utils
18 from linux import tasks
19 from linux import lists
20 from linux import vfs
21 from linux import rbtree
22 from struct import *
23
24
25 class LxCmdLine(gdb.Command):
26 """ Report the Linux Commandline used in the current kernel.
27 Equivalent to cat /proc/cmdline on a running target"""
28
29 def __init__(self):
30 super(LxCmdLine, self).__init__("lx-cmdline", gdb.COMMAND_DATA)
31
32 def invoke(self, arg, from_tty):
33 gdb.write(gdb.parse_and_eval("saved_command_line").string() + "\n")
34
35
36 LxCmdLine()
37
38
39 class LxVersion(gdb.Command):
40 """ Report the Linux Version of the current kernel.
41 Equivalent to cat /proc/version on a running target"""
42
43 def __init__(self):
44 super(LxVersion, self).__init__("lx-version", gdb.COMMAND_DATA)
45
46 def invoke(self, arg, from_tty):
47 # linux_banner should contain a newline
48 gdb.write(gdb.parse_and_eval("(char *)linux_banner").string())
49
50
51 LxVersion()
52
53
54 # Resource Structure Printers
55 # /proc/iomem
56 # /proc/ioports
57
58 def get_resources(resource, depth):
59 while resource:
60 yield resource, depth
61
62 child = resource['child']
63 if child:
64 for res, deep in get_resources(child, depth + 1):
65 yield res, deep
66
67 resource = resource['sibling']
68
69
70 def show_lx_resources(resource_str):
71 resource = gdb.parse_and_eval(resource_str)
72 width = 4 if resource['end'] < 0x10000 else 8
73 # Iterate straight to the first child
74 for res, depth in get_resources(resource['child'], 0):
75 start = int(res['start'])
76 end = int(res['end'])
77 gdb.write(" " * depth * 2 +
78 "{0:0{1}x}-".format(start, width) +
79 "{0:0{1}x} : ".format(end, width) +
80 res['name'].string() + "\n")
81
82
83 class LxIOMem(gdb.Command):
84 """Identify the IO memory resource locations defined by the kernel
85
86 Equivalent to cat /proc/iomem on a running target"""
87
88 def __init__(self):
89 super(LxIOMem, self).__init__("lx-iomem", gdb.COMMAND_DATA)
90
91 def invoke(self, arg, from_tty):
92 return show_lx_resources("iomem_resource")
93
94
95 LxIOMem()
96
97
98 class LxIOPorts(gdb.Command):
99 """Identify the IO port resource locations defined by the kernel
100
101 Equivalent to cat /proc/ioports on a running target"""
102
103 def __init__(self):
104 super(LxIOPorts, self).__init__("lx-ioports", gdb.COMMAND_DATA)
105
106 def invoke(self, arg, from_tty):
107 return show_lx_resources("ioport_resource")
108
109
110 LxIOPorts()
111
112
113 # Mount namespace viewer
114 # /proc/mounts
115
116 def info_opts(lst, opt):
117 opts = ""
118 for key, string in lst.items():
119 if opt & key:
120 opts += string
121 return opts
122
123
124 FS_INFO = {constants.LX_SB_SYNCHRONOUS: ",sync",
125 constants.LX_SB_MANDLOCK: ",mand",
126 constants.LX_SB_DIRSYNC: ",dirsync",
127 constants.LX_SB_NOATIME: ",noatime",
128 constants.LX_SB_NODIRATIME: ",nodiratime"}
129
130 MNT_INFO = {constants.LX_MNT_NOSUID: ",nosuid",
131 constants.LX_MNT_NODEV: ",nodev",
132 constants.LX_MNT_NOEXEC: ",noexec",
133 constants.LX_MNT_NOATIME: ",noatime",
134 constants.LX_MNT_NODIRATIME: ",nodiratime",
135 constants.LX_MNT_RELATIME: ",relatime"}
136
137 mount_type = utils.CachedType("struct mount")
138 mount_ptr_type = mount_type.get_type().pointer()
139
140
141 class LxMounts(gdb.Command):
142 """Report the VFS mounts of the current process namespace.
143
144 Equivalent to cat /proc/mounts on a running target
145 An integer value can be supplied to display the mount
146 values of that process namespace"""
147
148 def __init__(self):
149 super(LxMounts, self).__init__("lx-mounts", gdb.COMMAND_DATA)
150
151 # Equivalent to proc_namespace.c:show_vfsmnt
152 # However, that has the ability to call into s_op functions
153 # whereas we cannot and must make do with the information we can obtain.
154 def invoke(self, arg, from_tty):
155 argv = gdb.string_to_argv(arg)
156 if len(argv) >= 1:
157 try:
158 pid = int(argv[0])
159 except gdb.error:
160 raise gdb.GdbError("Provide a PID as integer value")
161 else:
162 pid = 1
163
164 task = tasks.get_task_by_pid(pid)
165 if not task:
166 raise gdb.GdbError("Couldn't find a process with PID {}"
167 .format(pid))
168
169 namespace = task['nsproxy']['mnt_ns']
170 if not namespace:
171 raise gdb.GdbError("No namespace for current process")
172
173 gdb.write("{:^18} {:^15} {:>9} {} {} options\n".format(
174 "mount", "super_block", "devname", "pathname", "fstype"))
175
176 for mnt in rbtree.rb_inorder_for_each_entry(namespace['mounts'], mount_ptr_type, "mnt_node"):
177 devname = mnt['mnt_devname'].string()
178 devname = devname if devname else "none"
179
180 pathname = ""
181 parent = mnt
182 while True:
183 mntpoint = parent['mnt_mountpoint']
184 pathname = vfs.dentry_name(mntpoint) + pathname
185 if (parent == parent['mnt_parent']):
186 break
187 parent = parent['mnt_parent']
188
189 if (pathname == ""):
190 pathname = "/"
191
192 superblock = mnt['mnt']['mnt_sb']
193 fstype = superblock['s_type']['name'].string()
194 s_flags = int(superblock['s_flags'])
195 m_flags = int(mnt['mnt']['mnt_flags'])
196 rd = "ro" if (s_flags & constants.LX_SB_RDONLY) else "rw"
197
198 gdb.write("{} {} {} {} {} {}{}{} 0 0\n".format(
199 mnt.format_string(), superblock.format_string(), devname,
200 pathname, fstype, rd, info_opts(FS_INFO, s_flags),
201 info_opts(MNT_INFO, m_flags)))
202
203
204 LxMounts()
205
206
207 class LxFdtDump(gdb.Command):
208 """Output Flattened Device Tree header and dump FDT blob to the filename
209 specified as the command argument. Equivalent to
210 'cat /proc/fdt > fdtdump.dtb' on a running target"""
211
212 def __init__(self):
213 super(LxFdtDump, self).__init__("lx-fdtdump", gdb.COMMAND_DATA,
214 gdb.COMPLETE_FILENAME)
215
216 def fdthdr_to_cpu(self, fdt_header):
217
218 fdt_header_be = ">IIIIIII"
219 fdt_header_le = "<IIIIIII"
220
221 if utils.get_target_endianness() == 1:
222 output_fmt = fdt_header_le
223 else:
224 output_fmt = fdt_header_be
225
226 return unpack(output_fmt, pack(fdt_header_be,
227 fdt_header['magic'],
228 fdt_header['totalsize'],
229 fdt_header['off_dt_struct'],
230 fdt_header['off_dt_strings'],
231 fdt_header['off_mem_rsvmap'],
232 fdt_header['version'],
233 fdt_header['last_comp_version']))
234
235 def invoke(self, arg, from_tty):
236
237 if not constants.LX_CONFIG_OF:
238 raise gdb.GdbError("Kernel not compiled with CONFIG_OF\n")
239
240 if len(arg) == 0:
241 filename = "fdtdump.dtb"
242 else:
243 filename = arg
244
245 py_fdt_header_ptr = gdb.parse_and_eval(
246 "(const struct fdt_header *) initial_boot_params")
247 py_fdt_header = py_fdt_header_ptr.dereference()
248
249 fdt_header = self.fdthdr_to_cpu(py_fdt_header)
250
251 if fdt_header[0] != constants.LX_OF_DT_HEADER:
252 raise gdb.GdbError("No flattened device tree magic found\n")
253
254 gdb.write("fdt_magic: 0x{:02X}\n".format(fdt_header[0]))
255 gdb.write("fdt_totalsize: 0x{:02X}\n".format(fdt_header[1]))
256 gdb.write("off_dt_struct: 0x{:02X}\n".format(fdt_header[2]))
257 gdb.write("off_dt_strings: 0x{:02X}\n".format(fdt_header[3]))
258 gdb.write("off_mem_rsvmap: 0x{:02X}\n".format(fdt_header[4]))
259 gdb.write("version: {}\n".format(fdt_header[5]))
260 gdb.write("last_comp_version: {}\n".format(fdt_header[6]))
261
262 inf = gdb.inferiors()[0]
263 fdt_buf = utils.read_memoryview(inf, py_fdt_header_ptr,
264 fdt_header[1]).tobytes()
265
266 try:
267 f = open(filename, 'wb')
268 except gdb.error:
269 raise gdb.GdbError("Could not open file to dump fdt")
270
271 f.write(fdt_buf)
272 f.close()
273
274 gdb.write("Dumped fdt blob to " + filename + "\n")
275
276
277 LxFdtDump()
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